/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.classfile;

import proguard.classfile.attribute.visitor.AttributeVisitor;
import proguard.classfile.constant.visitor.ConstantVisitor;
import proguard.classfile.util.*;
import proguard.classfile.visitor.*;

/**
 * This Clazz is a compact representation of the essential data in a Java class.
 *
 * @author Eric Lafortune
 */
public class LibraryClass implements Clazz {
    public int u2accessFlags;
    public String thisClassName;
    public String superClassName;
    public String[] interfaceNames;
    public LibraryField[] fields;
    public LibraryMethod[] methods;

    /**
     * An extra field pointing to the superclass of this class. This field is filled out by the
     * {@link ClassSuperHierarchyInitializer}.
     */
    public Clazz superClass;

    /**
     * An extra field pointing to the interfaces of this class. This field is filled out by the
     * {@link ClassSuperHierarchyInitializer}.
     */
    public Clazz[] interfaceClasses;

    /**
     * An extra field pointing to the subclasses of this class. This field is filled out by the
     * {@link ClassSubHierarchyInitializer}.
     */
    public Clazz[] subClasses;

    /**
     * An extra field in which visitors can store information.
     */
    public Object visitorInfo;

    /**
     * Creates an empty LibraryClass.
     */
    public LibraryClass() {}

    /**
     * Returns whether this library class is visible to the outside world.
     */
    boolean isVisible() {
        return (u2accessFlags & ClassConstants.ACC_PUBLIC) != 0;
    }

    // Implementations for Clazz.

    public int getAccessFlags() {
        return u2accessFlags;
    }

    public String getName() {
        return thisClassName;
    }

    public String getSuperName() {
        // This may be java/lang/Object, in which case there is no super.
        return superClassName;
    }

    public int getInterfaceCount() {
        return interfaceClasses.length;
    }

    public String getInterfaceName(int index) {
        return interfaceNames[index];
    }

    public int getTag(int constantIndex) {
        throw new UnsupportedOperationException("Library class [" + thisClassName + "] doesn't store constant pool");
    }

    public String getString(int constantIndex) {
        throw new UnsupportedOperationException("Library class [" + thisClassName + "] doesn't store constant pool");
    }

    public String getStringString(int constantIndex) {
        throw new UnsupportedOperationException("Library class [" + thisClassName + "] doesn't store constant pool");
    }

    public String getClassName(int constantIndex) {
        throw new UnsupportedOperationException("Library class [" + thisClassName + "] doesn't store constant pool");
    }

    public String getName(int constantIndex) {
        throw new UnsupportedOperationException("Library class [" + thisClassName + "] doesn't store constant pool");
    }

    public String getType(int constantIndex) {
        throw new UnsupportedOperationException("Library class [" + thisClassName + "] doesn't store constant pool");
    }

    public String getRefClassName(int constantIndex) {
        throw new UnsupportedOperationException("Library class [" + thisClassName + "] doesn't store constant pool");
    }

    public String getRefName(int constantIndex) {
        throw new UnsupportedOperationException("Library class [" + thisClassName + "] doesn't store constant pool");
    }

    public String getRefType(int constantIndex) {
        throw new UnsupportedOperationException("Library class [" + thisClassName + "] doesn't store constant pool");
    }

    public void addSubClass(Clazz clazz) {
        if (subClasses == null) {
            subClasses = new Clazz[1];
        } else {
            // Copy the old elements into new larger array.
            Clazz[] temp = new Clazz[subClasses.length + 1];
            System.arraycopy(subClasses, 0, temp, 0, subClasses.length);
            subClasses = temp;
        }

        subClasses[subClasses.length - 1] = clazz;
    }

    public Clazz getSuperClass() {
        return superClass;
    }

    public Clazz getInterface(int index) {
        return interfaceClasses[index];
    }

    public boolean extends_(Clazz clazz) {
        if (this.equals(clazz)) {
            return true;
        }

        return superClass != null && superClass.extends_(clazz);
    }

    public boolean extends_(String className) {
        if (getName().equals(className)) {
            return true;
        }

        return superClass != null && superClass.extends_(className);
    }

    public boolean extendsOrImplements(Clazz clazz) {
        if (this.equals(clazz)) {
            return true;
        }

        if (superClass != null && superClass.extendsOrImplements(clazz)) {
            return true;
        }

        if (interfaceClasses != null) {
            for (int index = 0; index < interfaceClasses.length; index++) {
                Clazz interfaceClass = interfaceClasses[index];
                if (interfaceClass != null && interfaceClass.extendsOrImplements(clazz)) {
                    return true;
                }
            }
        }

        return false;
    }

    public boolean extendsOrImplements(String className) {
        if (getName().equals(className)) {
            return true;
        }

        if (superClass != null && superClass.extendsOrImplements(className)) {
            return true;
        }

        if (interfaceClasses != null) {
            for (int index = 0; index < interfaceClasses.length; index++) {
                Clazz interfaceClass = interfaceClasses[index];
                if (interfaceClass != null && interfaceClass.extendsOrImplements(className)) {
                    return true;
                }
            }
        }

        return false;
    }

    public Field findField(String name, String descriptor) {
        for (int index = 0; index < fields.length; index++) {
            Field field = fields[index];
            if (field != null && (name == null || field.getName(this).equals(name))
                && (descriptor == null || field.getDescriptor(this).equals(descriptor))) {
                return field;
            }
        }

        return null;
    }

    public Method findMethod(String name, String descriptor) {
        for (int index = 0; index < methods.length; index++) {
            Method method = methods[index];
            if (method != null && (name == null || method.getName(this).equals(name))
                && (descriptor == null || method.getDescriptor(this).equals(descriptor))) {
                return method;
            }
        }

        return null;
    }

    public void accept(ClassVisitor classVisitor) {
        classVisitor.visitLibraryClass(this);
    }

    public void hierarchyAccept(boolean visitThisClass, boolean visitSuperClass, boolean visitInterfaces,
        boolean visitSubclasses, ClassVisitor classVisitor) {
        // First visit the current classfile.
        if (visitThisClass) {
            accept(classVisitor);
        }

        // Then visit its superclass, recursively.
        if (visitSuperClass) {
            if (superClass != null) {
                superClass.hierarchyAccept(true, true, visitInterfaces, false, classVisitor);
            }
        }

        // Then visit its interfaces, recursively.
        if (visitInterfaces) {
            // Visit the interfaces of the superclasses, if we haven't done so yet.
            if (!visitSuperClass) {
                if (superClass != null) {
                    superClass.hierarchyAccept(false, false, true, false, classVisitor);
                }
            }

            // Visit the interfaces.
            if (interfaceClasses != null) {
                for (int index = 0; index < interfaceClasses.length; index++) {
                    Clazz interfaceClass = interfaceClasses[index];
                    if (interfaceClass != null) {
                        interfaceClass.hierarchyAccept(true, false, true, false, classVisitor);
                    }
                }
            }
        }

        // Then visit its subclasses, recursively.
        if (visitSubclasses) {
            if (subClasses != null) {
                for (int index = 0; index < subClasses.length; index++) {
                    subClasses[index].hierarchyAccept(true, false, false, true, classVisitor);
                }
            }
        }
    }

    /**
     * Lets the given class visitor visit the superclass, if it is known.
     * 
     * @param classVisitor the <code>ClassVisitor</code> that will visit the superclass.
     */
    public void superClassAccept(ClassVisitor classVisitor) {
        if (superClass != null) {
            superClass.accept(classVisitor);
        }
    }

    /**
     * Lets the given class visitor visit all known direct interfaces.
     * 
     * @param classVisitor the <code>ClassVisitor</code> that will visit the interfaces.
     */
    public void interfacesAccept(ClassVisitor classVisitor) {
        if (interfaceClasses != null) {
            for (int index = 0; index < interfaceClasses.length; index++) {
                Clazz interfaceClass = interfaceClasses[index];
                if (interfaceClass != null) {
                    interfaceClass.accept(classVisitor);
                }
            }
        }
    }

    public void subclassesAccept(ClassVisitor classVisitor) {
        if (subClasses != null) {
            for (int index = 0; index < subClasses.length; index++) {
                subClasses[index].accept(classVisitor);
            }
        }
    }

    public void constantPoolEntriesAccept(ConstantVisitor constantVisitor) {
        // This class doesn't keep references to its constant pool entries.
    }

    public void constantPoolEntryAccept(int index, ConstantVisitor constantVisitor) {
        // This class doesn't keep references to its constant pool entries.
    }

    public void thisClassConstantAccept(ConstantVisitor constantVisitor) {
        // This class doesn't keep references to its constant pool entries.
    }

    public void superClassConstantAccept(ConstantVisitor constantVisitor) {
        // This class doesn't keep references to its constant pool entries.
    }

    public void interfaceConstantsAccept(ConstantVisitor constantVisitor) {
        // This class doesn't keep references to its constant pool entries.
    }

    public void fieldsAccept(MemberVisitor memberVisitor) {
        for (int index = 0; index < fields.length; index++) {
            Field field = fields[index];
            if (field != null) {
                field.accept(this, memberVisitor);
            }
        }
    }

    public void fieldAccept(String name, String descriptor, MemberVisitor memberVisitor) {
        Field field = findField(name, descriptor);
        if (field != null) {
            field.accept(this, memberVisitor);
        }
    }

    public void methodsAccept(MemberVisitor memberVisitor) {
        for (int index = 0; index < methods.length; index++) {
            Method method = methods[index];
            if (method != null) {
                method.accept(this, memberVisitor);
            }
        }
    }

    public void methodAccept(String name, String descriptor, MemberVisitor memberVisitor) {
        Method method = findMethod(name, descriptor);
        if (method != null) {
            method.accept(this, memberVisitor);
        }
    }

    public boolean mayHaveImplementations(Method method) {
        return (u2accessFlags & ClassConstants.ACC_FINAL) == 0 && (method == null || ((method.getAccessFlags()
            & (ClassConstants.ACC_PRIVATE | ClassConstants.ACC_STATIC | ClassConstants.ACC_FINAL)) == 0
            && !method.getName(this).equals(ClassConstants.METHOD_NAME_INIT)));
    }

    public void attributesAccept(AttributeVisitor attributeVisitor) {
        throw new UnsupportedOperationException("Library class [" + thisClassName + "] doesn't store attributes");
    }

    public void attributeAccept(String name, AttributeVisitor attributeVisitor) {
        throw new UnsupportedOperationException("Library class [" + thisClassName + "] doesn't store attributes");
    }

    // Implementations for VisitorAccepter.

    public Object getVisitorInfo() {
        return visitorInfo;
    }

    public void setVisitorInfo(Object visitorInfo) {
        this.visitorInfo = visitorInfo;
    }

    // Implementations for Object.

    public String toString() {
        return "LibraryClass(" + getName() + ")";
    }
}
